Influence of Austenitizing Temperature on the Microstructure and Corrosion Resistance of 55Cr18Mo1VN High-Nitrogen Plastic Mould Steel

作     者：Hua-Bing Li Wei-Chao Jiao Hao Feng Zhou-Hua Jiang Cui-Dong Ren 无

作者机构：School of MetallurgyNortheastern University Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education)Northeastern University 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2016年第29卷第12期

页      面：1148-1160页

核心收录：

学科分类：08[工学] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0802[工学-机械工程] 0703[理学-化学] 0811[工学-控制科学与工程] 

基　　金：financially supported by National Natural Science Foundation of China (Grant Nos.51304041, 51434004 and U1435205) Fundamental Research Funds for the Central Universities (Grant No. N150204007) 

主　　题：High-nitrogen plastic mould steel Austenitizing temperature Microstructure Corrosion resistance Cr-depleted zone 

摘      要：The influence of austenitizing temperature on the microstructure and corrosion resistance of 55Cr18MolVN high-nitrogen plastic mould steel was investigated. The microstructure, elemental distribution and Cr-depleted zone of different heat-treated samples were investigated by X-ray diffraction, electron probe microanalyzer analysis, and trans- mission electron microscopy. The corrosion resistance was evaluated using electrochemical measurements, and the analysis of passive film was carded out by X-ray photoelectron spectroscopy. The results indicated that the volume fraction of precipitates decreased, and the homogeneity of elements was improved with increasing austenitizing temperature. The degree of Cr-depleted zone around coarse M23C6 was severer than that around M2N, and pitting corrosion initiated preferentially around M23C6. The corrosion resistance of the samples increased with the austenitizing temperature. With the increase in austenitizing temperature, the passive film was thickened and Cr（III）cr2O3 in the inner layer of passive film was enriched, which enhanced the corrosion resistance of the steel. The higher content of nitrogen in solid solution at higher austenitizing temperature contributed to the increased intensity of CrN and NH3, leading to the increase in pH value in the pit, and promoting the repassivation of 55Cr18Mo1N steel.